Page:An introduction to ethics.djvu/34

 not with the passion of the South Italian; he will be imaginative, but without the mental symbolism of the Oriental. But his pack includes also those more particular characteristics which he has inherited directly from his parents—peculiar features in which he resembles them, and which mark him off as their son. And lastly, the pack will contain some elements which it is impossible to assign to any determinate quarter. These characteristics will be found in his pack, and in his alone. They are the peculiarities and idiosyncrasies which belong to him alone, and which differentiate him from all other people, even from his parents and brothers.

The proportion of this comprehensive inheritance that is due to the various generations of the child's ancestors has been calculated; and may be stated most conveniently in the form in which it was formulated by Sir Francis Galton in his Law of Ancestral Inheritance. Galton showed that on the average in every inheritance the two parents together contribute one half, the grandparents between them one quarter, and so on in the regular series ½ + ¼ + ⅛ + &hellip; This law holds good on the whole, but it gives no guidance in dealing with particular cases.

Heredity involves two aspects. "The hereditary relation is such that like tends to beget like, white at the same time opportunity is afforded for the individual new departures which we call variations. Both the tendency to persist and the tendency to diverge are included in the hereditary relation, so that it is confusing to make an absolute antithesis between heredity and variation. Heredity, seen in